The present invention relates generally to networking.
Network discovery generally allows a device, e.g., a network element such as a computer that is part of a network, to effectively detect other devices on the network. In other words, network discovery allows a device within a network to essentially discover the topology of the network. Network discovery is often a challenging task, particularly in relatively large networks in which there are many devices.
Network discovery may be implemented using a variety of different methods. Such methods, however, have drawbacks. For example, although a “ping sweep” method is generally capable of discovering substantially all devices in a network by testing substantially every Internet protocol (IP) address within a range, such testing generally consumes a significant number of resources and, thus, places a significant load on the network. Hence, a ping sweep method is not frequently implemented, resulting in some new devices within a network not being discovered substantially in real-time.
A layer 2 discovery protocol allows a device to advertise its identity and capabilities on a network and to detect and store the identity and capabilities of neighboring devices on the local network. The Link Layer Discovery Protocol (LLDP) is a vendor-neutral Layer 2 protocol that allows the previously described functions. The protocol was formally ratified as IEEE standard 802.1AB-2005 in May 2005. In general, LLDP allows each device to advertise information about itself to neighboring devices in the network, and stores information it discovers from the neighboring devices. LLDP-based discovery is generally effective in allowing devices within a network to be discovered, provided that the devices have LLDP turned “on” or otherwise deployed. However, not all devices in a network have LLDP turned on. For example, older devices may not support LLDP. As such, LLDP-based discovery may be unable to discover substantially all devices within a network.